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Frontiers in Oral Health 2024The study aimed to evaluate the impact of tobacco use on the composition and functions of the oral microbiome in healthy adult humans. (Review)
Review
OBJECTIVE
The study aimed to evaluate the impact of tobacco use on the composition and functions of the oral microbiome in healthy adult humans.
METHODS
We conducted a systematic search on PubMed, Web of Science, and Cinhal databases for literature published until 15 December 2023, to identify studies that have evaluated the oral microbiome with culture-independent next-generation techniques comparing the oral microbiome of tobacco users and non-users. The search followed the PECO format. The outcomes included changes in microbial diversity and abundance of microbial taxa. The quality assessment was performed using the Newcastle-Ottawa Scale (NOS) (PROSPERO ID CRD42022340151).
RESULTS
Out of 2,435 articles screened, 36 articles satisfied the eligibility criteria and were selected for full-text review. Despite differences in design, quality, and population characteristics, most studies reported an increase in bacterial diversity and richness in tobacco users. The most notable bacterial taxa enriched in users were and at the phylum level and , , and at the genus level. At the functional level, more similarities could be noted; and were increased in tobacco users compared to non-users. Most of the studies were of good quality on the NOS scale.
CONCLUSION
Tobacco smoking influences oral microbial community harmony, and it shows a definitive shift towards a proinflammatory milieu. Heterogeneities were detected due to sampling and other methodological differences, emphasizing the need for greater quality research using standardized methods and reporting.
SYSTEMATIC REVIEW REGISTRATION
CRD42022340151.
PubMed: 38445094
DOI: 10.3389/froh.2024.1310334 -
Brain, Behavior, and Immunity May 2024Gut microbiota communicates bidirectionally with the brain through the nervous, immune, and endocrine systems of the gut. In our preliminary study, the fecal microbiota...
Gut microbiota communicates bidirectionally with the brain through the nervous, immune, and endocrine systems of the gut. In our preliminary study, the fecal microbiota of volunteers with mild cognitive impairment (Fmci) exhibited a higher abundance of Escherichia fergusonii (NK2001), Veillonella infantium (NK2002), and Enterococcus faecium (NK2003) populations compared with those of healthy volunteers. Therefore, we examined the effects of Fmci, NK2001 (gram-negative), NK2002 (gram-negative-like), and NK2003 (gram-positive) on cognitive impairment-like behavior, neuroinflammation, and colitis in mice with or without antibiotics. Fmci transplantation increased cognitive impairment-like behavior, hippocampal tumor necrosis factor (TNF)-α expression, and the size of toll-like receptor (TLR)4Iba1, TLR2Iba1, and NF-κBIba1 cell populations independent of antibiotic treatment. Oral gavage of NK2001, NK2002, or NK2003, which induced TNF-α expression in Caco-2 cells, significantly increased cognitive impairment-like behavior and hippocampal TNF-α expression and Iba1-positive cell populations and decreased brain-derived neurotrophic factor (BDNF) expression in mice. Celiac vagotomy significantly decreased NK2001- or NK2002-induced cognitive impairment-like behavior and hippocampal Iba1 cell population and TNF-α expression and increased NK2001- or NK2002-suppressed hippocampal BDNF expression. However, NK2003-induced cognitive impairment-like behavior and hippocampal Iba1 cell population and TNF-α expression were partially, but not significantly, attenuated by celiac vagotomy. Furthermore, celiac vagotomy did not affect NK2001-, NK2002-, or NK2003-induced lipopolysaccharide (LPS) levels in the blood and feces and TNF-α expression and NF-κB-positive cell population in the colon. In conclusion, LPS-producing NK2001 and NK2002 and LPS-nonproducing NK2003 may induce NF-κB-mediated neuroinflammation through the translocation of byproducts such as LPS and peptidoglycan into the brain through gut-blood/vagus nerve-brain and gut-blood-brain pathways, respectively, resulting in cognitive impairment.
Topics: Humans; Mice; Animals; Lipopolysaccharides; NF-kappa B; Brain-Derived Neurotrophic Factor; Tumor Necrosis Factor-alpha; Neuroinflammatory Diseases; Caco-2 Cells; Cognitive Dysfunction; Vagus Nerve; Mice, Inbred C57BL; Escherichia; Veillonella
PubMed: 38428648
DOI: 10.1016/j.bbi.2024.02.031 -
Frontiers in Microbiology 2023Autism spectrum disorder (ASD) is associated with alterations in the gut microbiome. However, there are few studies on gut microbiota of children with ASD in China, and...
BACKGROUND
Autism spectrum disorder (ASD) is associated with alterations in the gut microbiome. However, there are few studies on gut microbiota of children with ASD in China, and there is a lack of consensus on the changes of bacterial species.
PURPOSE
Autism spectrum disorder (ASD) is associated with alterations in the gut microbiome. However, there are few studies on gut microbiota of children with ASD in China, and there is a lack of consensus on the changes of bacterial species.
METHODS
We used 16S rRNA sequencing to analyze ASD children (2 to 12 years), HC (2 to 12 years).
RESULTS
Our findings showed that the α-diversity, composition, and relative abundance of gut microbiota in the ASD group were significantly different from those in the HC groups. Compared with the HC group, the α-diversity in the ASD group was significantly decreased. At the genus level, the relative abundance of g_Faecalibacterium, g_Blautia, g_Eubacterium_eligens_group, g_Parasutterella, g_Lachnospiraceae_NK4A136_group and g_Veillonella in ASD group was significantly increased than that in HC groups, while the relative abundance of g_Prevotella 9 and g_Agathobacter was significantly decreased than that in HC groups. In addition, KEGG pathway analysis showed that the microbial functional abnormalities in ASD patients were mainly concentrated in metabolic pathways related to fatty acid, amino acid metabolism and aromatic compound metabolism, and were partially involved in neurotransmitter metabolism.
CONCLUSION
This study revealed the characteristics of gut microbiota of Chinese children with ASD and provided further evidence of gut microbial dysbiosis in ASD.
PubMed: 38420215
DOI: 10.3389/fmicb.2023.1326870 -
Journal of Oral Microbiology 2024Nitrate (NO) has been suggested as a prebiotic for oral health. Evidence indicates dietary nitrate and nitrate supplements can increase the proportion of bacterial... (Review)
Review
BACKGROUND
Nitrate (NO) has been suggested as a prebiotic for oral health. Evidence indicates dietary nitrate and nitrate supplements can increase the proportion of bacterial genera associated with positive oral health whilst reducing bacteria implicated in oral disease(s). In contrast, chlorhexidine-containing mouthwashes, which are commonly used to treat oral infections, promote dysbiosis of the natural microflora and may induce antimicrobial resistance.
METHODS
A systematic review of the literature was undertaken, surrounding the effects of nitrate on the oral microbiota.
RESULTS
Overall, = 12 and studies found acute and chronic nitrate exposure increased (representatives of) health-associated and (67% and 58% of studies, respectively) whilst reducing periodontal disease-associated (33%). Additionally, caries-associated and decreased (25% for both genera). Nitrate also altered oral microbiome metabolism, causing an increase in pH levels ( = 5), which is beneficial to limit caries development. Secondary findings highlighted the benefits of nitrate for systemic health ( = 5).
CONCLUSIONS
More clinical trials are required to confirm the impact of nitrate on oral communities. However, these findings support the hypothesis that nitrate could be used as an oral health prebiotic. Future studies should investigate whether chlorhexidine-containing mouthwashes could be replaced or complemented by a nitrate-rich diet or nitrate supplementation.
PubMed: 38420038
DOI: 10.1080/20002297.2024.2322228 -
Frontiers in Nutrition 2023Very Low Birth Weight (VLBW) infants, born weighing less than 1,500 grams, are at risk for both gut dysbiosis and later neuropsychological developmental deficits....
INTRODUCTION
Very Low Birth Weight (VLBW) infants, born weighing less than 1,500 grams, are at risk for both gut dysbiosis and later neuropsychological developmental deficits. Behavioral effects, while related to neurodevelopment, are often more subtle and difficult to measure. The extent of later neurobehavioral consequences associated with such microbial dysbiosis has yet to be determined. We explored associations between the infants' gut microbiome and early childhood behavior at 4 years of age and identified the bacterial taxa through a multivariate analysis by linear models.
METHODS
Parents completed the Child Behavior Checklist (CBCL) focused on different DSM diagnostic categories: affective, anxiety, pervasive developmental, attention deficit/hyperactivity, and oppositional defiant. All the CBCL scores were corrected for gender, delivery method, gestational age, infant birth weight, occurrence of sepsis, and days on antibiotics prior statistical analyses. Canonical correlation analysis (CCA) was performed to determine the relationship between early life gut microbiome and the adjusted CBCL scores. The association of bacterial Amplicon sequence Variants (ASVs) to the CBCL scores were tested with multivariate analysis by linear models (MaAsLin).
RESULTS
Nineteen children who were previously born with very low birth weight and studied while hospitalized in the Neonatal Intensive Care Unit (NICU) were included in this study. Statistically significant associations were observed between early life gut bacteria such as , and to later behavior at 4 years. No significant association could be observed with early-life gut microbiome alpha diversity and behavioral measures at 4 years.
DISCUSSION
These preliminary observational data provide insight into the relationships between VLBW gut microbiome dysbiosis and childhood behavior. This study contributes to the literature on gut microbiome analysis by examining various behavioral domains using a standardized tool linked to the Diagnostic and Statistical Manual of Mental Disorders (DSM).
PubMed: 38419643
DOI: 10.3389/fnut.2023.1294549 -
Frontiers in Cellular and Infection... 2024Graves' disease (GD) is the most common cause of hyperthyroidism, and its pathogenesis remains incompletely elucidated. Numerous studies have implicated the gut...
BACKGROUND
Graves' disease (GD) is the most common cause of hyperthyroidism, and its pathogenesis remains incompletely elucidated. Numerous studies have implicated the gut microbiota in the development of thyroid disorders. This study employs Mendelian randomization analysis to investigate the characteristics of gut microbiota in GD patients, aiming to offer novel insights into the etiology and treatment of Graves' disease.
METHODS
Two-sample Mendelian randomization (MR) analysis was employed to assess the causal relationship between Graves' disease and the gut microbiota composition. Gut microbiota data were sourced from the international consortium MiBioGen, while Graves' disease data were obtained from FINNGEN. Eligible single nucleotide polymorphisms (SNPs) were selected as instrumental variables. Multiple analysis methods, including inverse variance-weighted (IVW), MR-Egger regression, weighted median, weighted mode, and MR-RAPS, were utilized. Sensitivity analyses were conducted employing MR-Egger intercept test, Cochran's Q test, and leave-one-out analysis as quality control measures.
RESULTS
The Mendelian randomization study conducted in a European population revealed a decreased risk of Graves' disease associated with (Odds ratio (OR) [95% confidence interval (CI)]: 0.89 [0.89 ~ 0.90], adjusted value: <0.001), (OR: [95% CI]: 0.555 [0.437 ~ 0.706], adjusted value: <0.001), and (OR [95% CI]: 0.632 [0.492 ~ 0.811], adjusted value: 0.016). No significant evidence of heterogeneity, or horizontal pleiotropy was detected. Furthermore, the preliminary MR analysis identified 13 bacterial species including group and group, exhibiting significant associations with Graves' disease onset, suggesting potential causal effects.
CONCLUSION
A causal relationship exists between gut microbiota and Graves' disease. , , and emerge as protective factors against Graves' disease development. Prospective probiotic supplementation may offer a novel avenue for adjunctive treatment in the management of Graves' disease in the future.
Topics: Humans; Bacteroidaceae; Bacteroides; Veillonella; Prospective Studies; Graves Disease; Genome-Wide Association Study
PubMed: 38404289
DOI: 10.3389/fcimb.2024.1288222 -
BMC Cancer Feb 2024Increasing evidence indicates that gut microbiota are closely related to prostate cancer. This study aims to assess the gut microbiota composition in patients with... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Increasing evidence indicates that gut microbiota are closely related to prostate cancer. This study aims to assess the gut microbiota composition in patients with prostate cancer compared to healthy participants, thereby advancing understanding of gut microbiota's role in prostate cancer.
METHODS
A systematic search was conducted across PubMed, Web of Science, and Embase databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The methodological quality of included studies was evaluated using the Newcastle-Ottawa Scale (NOS), and pertinent data were analyzed. The kappa score assessed interrater agreement.
RESULTS
This study encompassed seven research papers, involving 250 prostate cancer patients and 192 controls. The kappa was 0.93. Meta-analysis results showed that alpha-diversity of gut microbiota in prostate cancer patients was significantly lower than in the control group. In terms of gut microbiota abundance, the ratio of Proteobacteria, Bacteroidia, Clostridia, Bacteroidales, Clostridiales, Prevotellaceae, Lachnospiraceae, Prevotella, Escherichia-Shigella, Faecalibacterium, and Bacteroides was higher in prostate cancer patients. Conversely, the abundance ratio of Actinobacteria, Bacteroidetes, Firmicutes, Selenomonadales, Veillonella, and Megasphaera was higher in the control group.
CONCLUSION
Our study reveals differences in alpha-diversity and abundance of gut microbiota between patients with prostate cancer and controls, indicating gut microbiota dysbiosis in those with prostate cancer. However, given the limited quality and quantity of selected studies, further research is necessary to validate these findings.
Topics: Male; Humans; Gastrointestinal Microbiome; Bacteria; Dysbiosis; Prostatic Neoplasms
PubMed: 38402385
DOI: 10.1186/s12885-024-12018-x -
Nutrients Feb 2024Lipid metabolism dysregulation is a critical factor contributing to obesity. To counteract obesity-associated disorders, bariatric surgery is implemented as a very...
Lipid metabolism dysregulation is a critical factor contributing to obesity. To counteract obesity-associated disorders, bariatric surgery is implemented as a very effective method. However, surgery such as Roux-en-Y gastric bypass (RYGB) is irreversible, resulting in life-long changes to the digestive tract. The aim of the present study was to elucidate changes in the fecal microbiota before and after RYGB in relation to blood lipid profiles and proinflammatory IL-6. Here, we studied the long-term effects, up to six years after the RYGB procedure, on 15 patients' gut microbiomes and their post-surgery well-being, emphasizing the biological sex of the patients. The results showed improved health among the patients after surgery, which coincided with weight loss and improved lipid metabolism. Health changes were associated with decreased inflammation and significant alterations in the gut microbiome after surgery that differed between females and males. The Actinobacteriota phylum decreased in females and increased in males. Overall increases in the genera , , , , and , and decreases in , , , , , , and were observed. In conclusion, our findings indicate that there were long-term changes in the gut microbiota after RYGB, and shifts in the microbial taxa appeared to differ depending on sex, which should be investigated further in a larger cohort.
Topics: Humans; Male; Female; Gastric Bypass; Obesity, Morbid; Interleukin-6; Sweden; Obesity; Gastrointestinal Microbiome; Lactobacillales
PubMed: 38398821
DOI: 10.3390/nu16040498 -
Microbiology Spectrum Apr 2024The oral microbiome plays an important role in protecting oral health. Here, we established a controlled mixed-species biofilm model and used it to assess the impact of...
The oral microbiome plays an important role in protecting oral health. Here, we established a controlled mixed-species biofilm model and used it to assess the impact of glucose and lactate on the ability of , an acidogenic and aciduric species, to compete with commensal oral bacteria. A chemically defined medium was developed that supported the growth of and four common early colonizers of dental plaque: , , , and . Biofilms containing the early colonizers were developed in a continuous flow bioreactor, exposed to , and incubated for up to 7 days. The abundance of bacteria was estimated by quantitative polymerase chain reaction (qPCR). At high glucose and high lactate, the pH in bulk fluid rapidly decreased to approximately 5.2, and outgrew other species in biofilms. In low glucose and high lactate, the pH remained above 5.5, and was the most abundant species in biofilms. By contrast, in low glucose and low lactate, the pH remained above 6.0 throughout the experiment, and the microbial community in biofilms was relatively balanced. Fluorescence hybridization confirmed that all species were present in the biofilm and the majority of cells were viable using live/dead staining. These data demonstrate that carbon source concentration is critical for microbial homeostasis in model oral biofilms. Furthermore, we established an experimental system that can support the development of computational models to predict transitions to microbial dysbiosis based on metabolic interactions.IMPORTANCEWe developed a controlled (by removing host factor) dynamic system metabolically representative of early colonization of not measurable . Hypotheses on factors influencing colonization, such as community composition and inoculation sequence and the effect of metabolite concentrations, can be tested and used to predict the effect of interventions such as dietary modifications or the use of toothpaste or mouthwash on colonization. The defined model (species and medium) can be simulated in an model to explore more of the parameter space.
Topics: Streptococcus mutans; Lactic Acid; In Situ Hybridization, Fluorescence; Glucose; Biofilms
PubMed: 38376204
DOI: 10.1128/spectrum.03713-23 -
Scientific Reports Feb 2024The oral cavity is the portal of entry for many microorganisms that affect swine, and the swine oral fluid has been used as a specimen for the diagnosis of several...
The oral cavity is the portal of entry for many microorganisms that affect swine, and the swine oral fluid has been used as a specimen for the diagnosis of several infectious diseases. The oral microbiota has been shown to play important roles in humans, such as protection against non-indigenous bacteria. In swine, studies that have investigated the microbial composition of the oral cavity of pigs are scarce. This study aimed to characterize the oral fluid microbiota of weaned pigs from five commercial farms in Brazil and compare it to their respective fecal and environmental microbiotas. Bacterial compositions were determined by 16S rRNA gene sequencing and analyzed in R Studio. Oral fluid samples were significantly less diverse (alpha diversity) than pen floor and fecal samples (P < 0.01). Alpha diversity changed among farms in oral fluid and pen floor samples, but no differences were observed in fecal samples. Permutational ANOVA revealed that beta diversity was significantly different among sample types (P = 0.001) and farms (P = 0.001), with separation of sample types (feces, pen floor, and oral fluid) on the principal coordinates analysis. Most counts obtained from oral fluid samples were classified as Firmicutes (80.4%) and Proteobacteria (7.7%). The genera Streptococcus, members of the Pasteurellaceae family, and Veillonella were differentially abundant in oral fluid samples when compared to fecal samples, in which Streptococcus was identified as a core genus that was strongly correlated (SparCC) with other taxa. Firmicutes and Bacteroidota were the most relatively abundant phyla identified in fecal and pen floor samples, and Prevotella_9 was the most classified genus. No differentially abundant taxa were identified when comparing fecal samples and pen floor samples. We concluded that under the conditions of our study, the oral fluid microbiota of weaned piglets is different (beta diversity) and less diverse (alpha diversity) than the fecal and environmental microbiotas. Several differentially abundant taxa were identified in the oral fluid samples, and some have been described as important colonizers of the oral cavity in human microbiome studies. Further understanding of the relationship between the oral fluid microbiota and swine is necessary and would create opportunities for the development of innovative solutions that target the microbiota to improve swine health and production.
Topics: Swine; Animals; Humans; Gastrointestinal Microbiome; RNA, Ribosomal, 16S; Housing; Bacteria; Feces; Firmicutes
PubMed: 38374338
DOI: 10.1038/s41598-024-54269-5